#include<iostream>
#include<array>

using namespace std;

int main()
{
    array<double,3>grade;
    cin >> grade[0];
    cin >> grade[1];
    cin >> grade[2];
    int k = 3;
    double average = (grade[0] + grade[1] + grade[2]) / 3;
    cout << k << average << endl;

    return 0;
}